2010 Corvette Grand Sport, 3700mi Castrol GC 0w-30

[smonska]

Looks like GM LS engines LOVE German Castrol 0w-30! 3,700mi of not-so-nice treatment and my lowest wear metals yet. The oil could have gone twice as long considering TBN retention on this oil was amazing and the flashpoint and viscosity are very high too.

Car holds 11 quarts in a dry-sump system. Previous oil changes were Mobil 1 0w-40, PP 5w-30, and stock Mobil 1 5w-30.

This oil had 3 track days, at Pocono and Watkins Glen Speedways, on it. These Euro oils, 0w-30 and M1 0w-40 have more anti-wear elements, Zinc and Phosphorus, which I like. Oil pressure with oil temps of 240F at the track was not dramatically lower than when on the street, which I can't say for the 5-w30.

 

[901Memphis]

With TBN like that you could probably push 10k plus but we already know Gm engines throw lots of metal in the oil so 5000 might be the sweet spot like they recommend.

What oil filter did you use to achieve that low insolubles rating? Must be a FU.

 

[fdcg27]

Looks pretty nice, although the only thing realy our of line in your earlier UOAs was copper, which looks like its been trending down anyway.
What oils did you run prior to this?
Given that the engine was still breaking in, I don't think that you can attribute the reduced metal shedding in this UOA entirely to the GC, although it seems to do just fine in this engine.

 

[A_Harman]

Does your car have an oil cooler on it? Maybe the cooler is shedding copper. It's nice to see that it's getting progressively lower with each oil sample.

I've got GC 0w30 in my Camaro now, but probably won't be doing track days with it for a few months. I've had it in for about 3600 miles and have burned about a quart, which is the same as on PU. The engine on GC has more piston slap noise at warmed-up idle than PU. I think the higher viscosity is not allowing the oil to spray on the cylinder walls as well.

With 11 quarts in your oil system, you should be able to considerably extend the OCI. But since the engine is still young, doing regular UOA's and letting the results guide you is a good way to go.

 

[SilverC6]

It would be interesting to try PP 5W-30 again after everything gets worn in.

However, if you're tracking the car, the EURO Castrol 0W-30 might remain the best choice.

 

[smonska]

Oil filters have been nothing but the AC-Delco UPF48R made just for Z06, GS, and ZR1 Corvettes. I bought 6 at $8/ea. Similar to Delco PF48 but higher burst strength can (they are HEAVY) as these motors can touch 100psi when revved cold, and ostensibly better media.

 

[rhhsiao]

To be honest, I don't think you can draw a meaningful conclusion that your Corvette loves the GC. Metals are trending down since you're breaking things in. Of course your first few samples are going to show high metals. My feeling is that any good oil that meets the specs would have had similar results.

This isn't to say your engine doesn't like the GC, but rather, coming to a finite conclusion is a bit premature at this point as to which oil is "best".

 

[209paulc]

Extend to 5k OCI, a few track days...no big deal. LS engines perform well on GC. Well enough to convince Amsoil into comparing the oil to theirs in side-by-side UOA testing in a Corvette a few years back.